Identify the element for which electronic configuration in
Question:

Identify the element for which electronic configuration in $+3$ oxidation state is $[\mathrm{Ar}] 3 \mathrm{~d}^{5}:$

1. $\mathrm{Ru}$

2. $\mathrm{Mn}$

3. $\mathrm{Co}$

4. $\mathrm{Fe}$

Correct Option: , 4

Solution:

$\mathrm{Fe}^{3+}[\mathrm{Ar}] 3 \mathrm{~d}^{5}$